|Year : 2019 | Volume
| Issue : 2 | Page : 52-61
Preliminary study on the role of toll-like receptor-4 antagonist in treatment of Trichinella spiralis infection
Dina A Elguindy1, Dalia S Ashour1, Maha M Shamloula2, Ibrahim A Aboul Assad1
1 Medical Parasitology Department, Faculty of Medicine, Tanta University, Egypt
2 Pathology Department, Faculty of Medicine, Tanta University, Egypt
|Date of Submission||01-Apr-2018|
|Date of Acceptance||01-Apr-2019|
|Date of Web Publication||18-May-2020|
Dina A Elguindy
Demonstrator at Medical Parasitology Department, Faculty of Medicine, Tanta University
Background Trichinella spiralis is one of the most widespread zoonotic parasitic nematodes in the world. There is an increasing interest in developing new antihelminthic drugs for Trichinella. Toll-like receptor-4 (TLR4) is closely related to T. spiralis infection, and its deficiency is associated with rapid expulsion of T. spiralis worms.
Aim The aim of this study was to explore the effect of TLR4 antagonist (curcumin) on the course of experimental trichinellosis.
Materials and methods Mice were divided into two main groups. Group I was the control group (90 mice), which was subdivided into the following: subgroup Ia (10 mice), with noninfected nontreated mice (negative control); subgroup Ib (40 mice), with infected nontreated mice (positive control); and subgroup Ic (40 mice), with noninfected treated with curcumin. Group II was the infected and treated group (50 mice), where infected mice received curcumin starting 2 h after infection and continued for 10 successive days after infection. For each group, total adult and muscle larval count were estimated, and the small intestines and muscles were removed for further studies.
Results This results showed a significant decrease in the mean number of adults and larvae in the infected treated group compared with the infected control mice, with an extremely significant percentage of reduction of 53%. Regarding the histopathological changes, there was a marked increase in the inflammatory reaction surrounding the adult worms in the small intestines and the encysted larvae in muscles of the infected treated group compared with the infected nontreated group. Curcumin leads to degeneration of the capsule around the larvae in the skeletal muscles of the infected treated group. There was a significant increase in nuclear factor-κB expression by small intestinal tissues in T. spiralis infected treated group (group II) as compared with the infected nontreated group (group Ib).
Conclusion This study revealed that curcumin has an antiparasitic activity against both stages of T. spiralis. Thus, it could be a promising drug for treatment of T. spiralis infection.
Keywords: curcumin, nuclear factor-κB, Toll-like receptor-4, Trichinella spiralis
|How to cite this article:|
Elguindy DA, Ashour DS, Shamloula MM, Aboul Assad IA. Preliminary study on the role of toll-like receptor-4 antagonist in treatment of Trichinella spiralis infection. Tanta Med J 2019;47:52-61
|How to cite this URL:|
Elguindy DA, Ashour DS, Shamloula MM, Aboul Assad IA. Preliminary study on the role of toll-like receptor-4 antagonist in treatment of Trichinella spiralis infection. Tanta Med J [serial online] 2019 [cited 2021 Jan 28];47:52-61. Available from: http://www.tdj.eg.net/text.asp?2019/47/2/52/284494
| Introduction|| |
Trichinellosis is a zoonotic disease caused by eating undercooked or raw meat harboring the infective Trichinella larvae . It infects many mammalian, avian, and reptile host species, in which the adult worms and the larvae reside in the small intestinal and muscle tissues, respectively .
Trichinella infection in the human host is divided into two phases: an intestinal (or enteral) phase and a muscular (or parenteral) phase. Worms migrating in epithelium of the intestine can lead to traumatic damage to tissues of the host . The invading Trichinella newborn larvae produce muscle cell damage that triggers the activation of satellite cells undergoing proliferation and re-differentiation, thus producing nurse cell and encapsulation of the larvae with surrounding capillary rete ,. The resulting inflammation in the intestine and the muscles is associated with activation of nuclear factor-κB (NF-кB) signaling pathways . Although NF-κB promotes T-cell activation and differentiation, the function of NF-κB is paradoxical, as it is also involved in the generation of T regulatory (Treg) cells, thus has a protective role maintaining integrity of tissues ,. However, the persistence of infection indicates that Trichinella has manipulated the NF-κB signaling pathway to evade the host immune response .
T. spiralis can adjust the immune system to its advantage by activating or negatively regulating Toll-like receptor (TLRs) . It was found that Toll-like receptor-4 (TLR4)-deficient mice expel worms more rapidly, proving that TLR4 plays an important role in T. spiralis infection . It was suggested that ES antigens of T. spiralis interact with TLR4, inducing a tolerogenic status in dendritic cells (DCs) and as a result shift T-cell polarization toward the regulatory type. Activated Tregs can inhibit the specific response against the parasite as well as the autoantigens .
Curcumin which is extracted from the rhizome Curcuma longa has anti-inflammatory, anti-infection, antioxidant, and antitumor properties ,. Curcumin was found to be a TLR4 antagonist . Therefore, this study aimed to explore the role of curcumin on the enteral and parenteral phases of experimental T. spiralis infection, postulating that its effect potentiates it to be used as a safe treatment for trichinellosis.
| Materials and methods|| |
Parasite and animals
This study was conducted on 140 laboratory-bred male Swiss albino mice that were housed and fed according to the national guidelines. The strain of T. spiralis is maintained in the laboratory of Tanta Medical Parasitology Department by consecutive passages through rats and mice.
Curcumin (Sigma Aldrich, Cairo, Egypt) was given orally at 100 mg/kg/day dissolved in distilled water for 10 successive days .
The experiment was approved by the Research Ethics Committee, Quality Assurance Unit, Tanta Faculty of Medicine, Egypt. Mice were infected with T. spiralis larvae orally in a dose of 200 larvae per mouse according to Dunn and Wright . Animals were divided into two main groups: group I was the control group (90 mice), which was further subdivided into the following: subgroup Ia (10 mice) included noninfected nontreated mice, subgroup Ib (40 mice) included infected nontreated mice, and subgroup Ic (40 mice) included noninfected treated with curcumin for 10 days. Group II was the infected and treated group (50 mice), where infected mice received curcumin starting 2 h after infection and continued for 10 successive days after infection.
Five mice from each of the two infected groups (infected nontreated and infected treated) were killed twice weekly for 4 weeks starting from the fourth day after infection. The small intestine was removed, longitudinally opened, and cleaned with saline. Overall, 1 cm from the middle third of the small intestine was preserved in 10% formol-saline for histopathological and immunohistochemical studies. Five weeks after infection, muscle samples from the thigh muscles were obtained for histopathological and immunohistochemical studies. The rest of the skeletal muscle was used for total larval count. The negative control group (noninfected nontreated and noninfected treated) was killed once at the end of the experiment. All experiments were done in duplicate.
Adult worms count in small intestine
The remainder of the intestines of the infected treated and the infected nontreated groups were cut into 2 cm pieces and placed in a beaker full of normal physiological saline at 37°C for 3–4 h. After that, the intestine was shaken well in the solution and rinsed with saline. All the fluid was collected and centrifuged at 1500 rpm for 5 min. The worms were counted in the reconstituted sediment drop by drop at a magnification of ×40 .
Total larval burden in muscles
Five weeks after infection, five animals from each infected group were euthanized. The total muscle larvae were counted according to Wranicz et al. .
Tissue samples (intestinal and skeletal muscle) from the studied groups were prepared by routine histological processing, paraffin embedding, sectioning at 5-µm thickness, and staining by hematoxylin and eosin, and then routine evaluation of the histopathological characteristics and comparative descriptive analysis of the studied experimental groups were done .
Immunohistochemistry for nuclear factor-кB expression
Paraffin tissue sections were immunostained for NF-кB transcription factor by the biotin streptavidin-peroxidase method using the NF-кB p65 (F-6) monoclonal antibody (Santa Cruz Biotechnology, Santa Cruz, California, USA), which recognizes amino-terminal sequences of the p65 subunit. Nuclei were counterstained with hematoxylin. Substitution of the primary antibody with PBS served as the negative control. NF-кB staining was assessed by light microscopy and localized within the cell cytoplasm and/or nucleus. Positive reaction appears in the form of brownish staining with nuclear localization of NF-кB, which was categorized as positive or negative .
Quantitative data were presented as mean±SD. The probability of significant differences among groups was determined by one-way anal test. Differences were considered significant, when P value was less than 0.05. The statistical analyses were processed using statistical package of the social sciences (SPSS Inc., Chicago, Illinois, USA) software for Windows, version 10.0.
| Results|| |
Adult worms count in small intestine
The mean adult worm count in the small intestine on day 4 after infection of the infected nontreated group (group Ib) was 67±8, with no significant difference with that of the infected and treated group (group II) (60±9). Two weeks after infection, the mean adult worm of the infected treated group greatly declined, reaching 30.33±1.53, with percentage of reduction of 45.84%, as compared with the infected nontreated group (56±4). By the end of the fourth week, the percentage of reduction reached 81.44% with an extremely statistically significant difference (P<0.001) between the infected treated and infected nontreated groups ([Table 1]).
|Table 1 Adult worm count (mean±SD) of Trichinella spiralis in the small intestine of control and infected treated groups|
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Total larval counts in muscles
On day 35 after infection, there was an extremely statistically significant reduction of total larval counts in the infected treated group (26.169±4.48) as compared with infected nontreated group (56.128±13.07) (P<0.001), with percentage of reduction of 53%.
Small intestinal changes
The small intestinal sections of both noninfected nontreated and noninfected treated groups showed normal small intestinal structure, and no histopathological changes were observed. Small intestinal sections of the infected control group (group Ib) revealed the presence of adult worm sections within the mucosa with inflammatory cellular infiltration of the mucosa and the submucosa ([Figure 1]a). The infiltrate was mostly present in the core of the villi and in the submucosa and was mainly composed of lymphocytes, eosinophils, plasma cells, neutrophils, and fibroblasts together with villous blunting and edema and lymphoid follicle hyperplasia ([Figure 1]b). In addition, there was goblet cell hyperplasia ([Figure 1]c). Crypt abscess was also seen together with high mitosis in crypts ([Figure 1]d). Small intestinal sections of the infected treated group (group II) revealed similar histopathological changes; however, there was a marked increase in the inflammatory reaction surrounding the adult worms compared with the infected control group ([Figure 2]a–d).
|Figure 1 Small intestinal section of Trichinella spiralis-infected control mouse (group Ib) (hematoxylin and eosin) showing the following: (a) adult worm (arrow) within the mucosal crypts surrounded by inflammatory cells (×100); (b) villous edema with inflammatory cellular infiltrate in the villi cores (×100), goblet cells hyperplasia (arrows) with inflammatory cellular infiltrate in the villi cores, and submucosa (×200); and (d) crypt abscess (arrow) (×200).|
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|Figure 2 Small intestinal section of Trichinella spiralis-infected treated mouse (group II) (hematoxylin and eosin) showing the following: (a) marked increase in the inflammatory reaction surrounding the adult worms (×100), (b) villous edema (×200), (c) excessive inflammatory cellular infiltrate (×200), and (d) high mitotic count in the crypts (arrows) (×200).|
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Skeletal muscle changes
Normal muscle architecture was observed in the muscle sections of both noninfected nontreated and noninfected treated groups. However, muscle sections of the infected group (group Ib) revealed the presence of massive number of encysted T. spiralis larvae surrounded by thick capsule, which was surrounded by inflammatory cells such as lymphocytes, plasma cells, macrophages, histiocytes, neutrophils, and eosinophil’s ([Figure 3]a and b). Muscle sections of infected treated group (group II) showed much fewer numbers of encysted larvae and an increase in the inflammatory reaction surrounding the larvae, besides the capsule around the larvae showed splitting, thinning, and vacuolation ([Figure 3]c). Degenerative changes inside the muscles were seen in the form of loss of striation, hyaline appearance, and swelling ([Figure 3]d).
|Figure 3 Muscle section of Trichinella spiralis-infected control mouse (a and b) and infected treated mouse (c and d) (hematoxylin and eosin) showing the following: (a) large number of encysted larva inside muscle fibers surrounded by thick capsule and inflammatory cellular infiltrate (arrows) (×100); (b) higher magnification of encysted larva inside the muscles (×200); (c) heavy inflammatory cellular infiltrate surrounding encysted larva and its capsule showed areas of vacuolation (curved arrow), thinning out, and splitting (arrow) (×400); and (d) degenerated muscles in the form of swelling, loss of striation, and hyaline appearance (×100). Insit: higher magnification of (d) (×200).|
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Immunohistochemistry for nuclear factor-кB expression
Expression of nuclear factor-кB in small intestinal tissues
There was an increase in NF-кB expression in small intestinal tissues in the infected treated group (group II). The expression showed strong nuclear and/or cytoplasmic positivity in the enterocytes and inflammatory cells ([Figure 4]a and b). The infected nontreated group showed moderate nuclear and/or cytoplasmic positivity in the enterocytes and inflammatory cells ([Figure 4]c), with a highly statistically significant difference (P<0.001). However, the noninfected treated group showed weak expression ([Figure 4]d), and the noninfected nontreated was negative.
|Figure 4 Immunohistochemical expression of nuclear factor-κB in small intestine of Trichinella spiralis-infected treated mice (a and b), infected nontreated mice (c), and noninfected treated (d) (immunoperoxidase ×400) showing the following: (a) strong positivity in inflammatory cells and enterocytes; (b) strong positivity in inflammatory cells; (c) moderate positivity in inflammatory cells and enterocytes; and (d) weak nuclear staining in the submucosal inflammatory cells only.|
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Expression of nuclear factor-кB in the skeletal muscle tissues
There was an increase in NF-кB expression by the skeletal muscles in the infected treated group (group II). It showed strong positive expression (nuclear and/or cytoplasmic) in the sarcoplasm of the skeletal muscles as well as inflammatory cells ([Figure 5]a and b). However, infected nontreated and the noninfected treated groups showed mild nuclear positivity in the skeletal muscles sarcoplasm ([Figure 5]c). Regarding the noninfected nontreated group, the expression was negative.
|Figure 5 Immunohistochemical expression of nuclear factor-κB in muscle of Trichinella spiralis-infected treated mice (a and b) and infected nontreated mice (c) (immunoperoxidase ×400) showing the following: (a) strong cytoplasmic positivity in the sarcoplasm of the striated muscles (b) strong positivity in the inflammatory cells and positivity in the skeletal muscles.|
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| Discussion|| |
Several studies have elucidated the mechanisms of Trichinella adult worm expulsion from the intestine based mainly on the immune response against T. spiralis and the inflammatory response that plays a crucial role in the parasite expulsion because it makes the habitat hostile, thus facilitating worm expulsion with subsequent regulation of the muscle phase ,.
T. spiralis releases abundant glycoproteins throughout its life that activate immune cells or an immune response related to TLRs ,. The phosphorylcholine of the parasite binds to TLR4 . TLR4 is very closely related to T. spiralis infection, as the gene expression of TLR4 was elevated in the intestinal and muscular phases of mice affecting cytokine production . This study assessed the effect of TLR4 antagonist (curcumin) on the course of experimental trichinellosis.
Curcumin has been the subject of many research studies owing to its various pharmacological activities and biosafety . Curcumin is a TLR4 antagonist, as it inhibits TLR4 homodimerization, and it is a potent inhibitor of many signaling molecules in the TLR4 pathway .
This results showed a significant decrease in the mean number of adults in the infected treated group compared with the infected control mice, with percentages of reduction of 61.76 and 81.44% at the third and fourth weeks, respectively. Our results agree with Scalfone et al.  and Eckburg et al.  who stated that TLR4 deficiency produced rapid expulsion of T. spiralis worms, proving that these receptors are engaged in T. spiralis infection. Eckburg et al.  also mentioned that TLR4 deficiency impaired gut homeostasis that contributes to a “leaky gut,” thus promoting parasite expulsion.
In the same context, several studies have reported other antiparasitic effects of curcumin. Magalhaes et al.  mentioned that treatment with curcumin modulates humoral and cellular immune responses of Schistosoma mansoni-infected mice and leads to a significant reduction of parasite burden and liver pathology. Moreover, De Paula Aguiar et al.  mentioned that curcumin caused apoptosis and DNA fragmentation in adult worms of S. mansoni and induced the production of reactive oxygen species (ROS).
Lakkany and Seif El-Din  mentioned that in helminthes, numerous antioxidant systems regulate the concentrations of ROS inside the cell via different enzymes that play an essential part in the decomposition of ROS and protect the parasite from damage. De Paula Aguiar et al.  reported that the activities of these antioxidant enzyme were decreased in S. mansoni adult female and male worms incubated with curcumin; thus, the protein carbonyl content was highly elevated in adult worms. In other words, curcumin produces oxidative stress followed by apoptosis in adult S. mansoni worms, leading to parasite death. The same mechanism of action was reported in filariasis . Curcumin was found to act as both a macrofilaricide and microfilaricide, as it causes significant reduction in the viability of both adults and microfilariae. Although not investigated in the current study, curcumin may accomplish its antiparasitic effect against T. spiralis in the same way.
In this study, the mean total larval count of the infected treated group was greatly reduced as compared with that of the infected nontreated group, with a significant percentage of reduction of 53%. We propose that the decreased adult count subsequently resulted in reducing the larval count. In addition, curcumin produces an impairment of embryogenesis as reported by De Paula Aguiar et al. . They discovered that, under the effect of curcumin, some alterations took place, mostly in the vitellarium of S. mansoni female worms, which is the proliferative tissue that aids in the development of the embryo. Similarly, Mohapatra et al.  stated that curcumin induces apoptosis in embryonic stages of the nematode Setaria digitate. Curcumin causes chromatin condensation and DNA fragmentation in developing embryos and microfilariae in gravid female ROS leading to apoptosis. This promising strategy played by curcumin may produce effective antiparasitic measures .
Regarding the histopathological examination, intestinal sections of T. spiralis-infected nontreated group (group Ib) revealed inflammatory cells infiltrating the mucosa and the submucosa with villous edema. In addition, there were goblet cell hyperplasia, blunting of the villi, and lymphoid follicle hyperplasia. Crypt abscess was also seen together with high mitosis in crypts. These findings coincide with Airis et al.  who reported the same observations. Khan  stated that goblet cell hyperplasia takes place leading to increased secretion of mucus that helps in the defense mechanism by trapping the parasite in the mucus, thus decreasing the motility of the worm and in turn leads to parasite expulsion.
TLRs do not only promote the production of inflammatory molecules but they are also regulatory (anti-inflammatory) contributors [interleukin 10 (IL-10) and transforming growth factor-β (TGF-β)] ,. In other words, in T. spiralis infection, the modulated TLR expression in the small intestine is related to Treg cell-mediated immune responses and increased IL-10 and TGF-β gene expression . Lipopolysaccharide-bound TLR4 engages different adapter mechanisms to induce anti-inflammatory cytokines such as IL-10 . It was found that TGF-β works with IL-10 to control local inflammation, and their deficiency leads to severe inflammation in the muscles . Thus, it explains our finding that there was a marked increase in the intestinal inflammatory reaction in response to decreased TLR4 in the infected treated group compared with the infected nontreated group.
Muscle sections of the infected nontreated group (group Ib) revealed the presence of a massive number of encysted T. spiralis larvae surrounded by thick capsule and inflammatory cells, whereas the infected treated group (group II) showed much fewer numbers of encysted larvae and an increase in the inflammatory reaction surrounding the larvae with occasional abscess formation. Degenerative changes inside the muscles were seen in the form of loss of striation, hyaline appearance, and swelling, besides splitting, thinning, and vacuolation of the capsule around the larvae.
These results are similar to the findings of Bruschi and Chiumiento  which state that T. spiralis causes mechanical damage to the skeletal muscle cells as well as inflammatory cells accumulation, through the production of high levels of oxygen reactive species and other free radicals. Nurse cell formation is important for the larva to survive inside the skeletal muscle. Angiogenesis around the collagen capsule is required for maintaining the larvae within the host for long periods . The main factor promoting angiogenesis in trichinellosis is the vascular endothelial growth factor . Curcumin inhibits a variety of angiogenesis growth factors including vascular endothelial growth factor . Curcumin was able to inhibit the angiogenic response to fibroblast growth factor-2 stimulation in mouse endothelial cells . This interference with the angiogenesis process can deprive the larvae from their nutrition with accumulation of their wastes causing their death.
In this study, there was a marked increase in the inflammatory reaction in the muscles surrounding the larvae in response to decreased TLR4 in the infected treated group compared with the infected nontreated group. This marked increase in inflammation can explain the decrease in the number of both adult worms and larvae through the release of ROS and free radicals such as nitric oxide. Inflammatory cells release high levels of ROS and other free radicals .
There was a significant increase in NF-κB expression by small intestinal and muscle tissues in T. spiralis-infected treated group (group II) as compared with the infected nontreated group (group Ib). There was both nuclear and cytoplasmic positivity in the enterocytes, sarcoplasm of the skeletal muscles, as well as intestinal and muscle inflammatory cellular infiltrate. Although curcumin is reported to decrease NF-κB expression , our results showed that its expression was increased in the treated group mostly because of its massive expression from the increased inflammatory cells. These results agree with Ashour et al.  who stated that the degree of NF-κB activation correlates with the severity of inflammation. In this study, curcumin inhibited TLR4 and consequently increased inflammation, thus increasing NF-κB expression. NF-κB is located in the cytoplasm in most cell types, until induced by a stimulus to be activated and translocated in the nucleus .
In this study, curcumin was found to have an antiparasitic activity against T. spiralis and at the same time increase the inflammatory reactions both in the small intestine and muscles leading to significant reduction in the adult worm count and the larval burden, respectively.
Regarding the previous protocols used for treatment of T. spiralis, it has been proven that albendazole is active against the enteral and parenteral phase of the parasite in experimental trichinellosis but failed to act during the invasive and encystment phase, as it has a relatively low antiparasitic activity against encysted larvae . In addition, the efficacy of mebendazole against muscle larvae depends on the time between infection and treatment and could be dose dependent .
Therefore, medicinal plants could be used as alternative target for managing T. spiralis infection such as Nigella sativa , Artemisia vulgaris , and myrrh and thyme . The efficacy of curcumin in this study was higher than those of previous studies. This may be owing to its immunological effect as TLR4 inhibitor or because of the protocol used for treatment, that is, high doses, early administration, and during both the intestinal and muscular phases of infection for many successive days.
| Conclusion|| |
This study suggests that curcumin may act as a TLR4 antagonist and can be used in the treatment of trichinellosis. Curcumin was able to decrease the adult worm count and the larval count. However, an important limitation hindering the clinical advancement of curcumin as a promising molecule for treatment of T. spiralis is its limited oral bioavailability though it has a high tissue distribution . Thus, a successful enhancement of curcumin bioavailability is likely to bring this promising natural product to the forefront of therapeutic agents for the treatment of trichinellosis.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Wang ZQ, Shi YL, Liu RD, Jiang P, Guan YY, Chen YD, Cui J. New insights on serodiagnosis of trichinellosis during window period: early diagnostic antigens from Trichinella spiralis
intestinal worms. Infect Dis Poverty 2017; 6:41.
OIE. Terrestrial Manual of Diagnostic Tests and Vaccines, Chapter 2.1.16. Trichinellosis (2012).
Harbo JR, Hoopingarner RA. Honey bees (Hymenoptera: Apidae) in the United States that express resistance to Varroajacobsoni (Mesostigmata: Varroidae). J Econ Entomol 1997; 90:893–898.
Capo V, Despommier D, Polvere RI. Trichinella spiralis: vascular endothelial growth factor is up-regulated within the nurse cell during the early phase of its formation. J Parasitol 1998; 84:209–214.
Matsuo A, Wu Z, Nagano I, Takahashi Y. Five types of nuclei present in the capsule of Trichinella spiralis
. Parasitology 2000; 121:203–210.
Symeonidou I, Pappa S, Kourelis A, Anogeianaki A, Frydas I, Karagouni E, Hatzistilianou M. Microarray analysis of NF-kappaB signaling pathways in PBMC of mice infected by Trichinella spiralis
. Int J Immunopathol Pharmacol 2010; 23:821–831.
Nenci A, Becker C, Wullaert A, Gareus R, van Loo G, Danese S et al.
Epithelial NEMO links innate immunity to chronic intestinal inflammation. Nature 2007; 446:557–561.
Shi JH, Sun SC. TCR signaling to NF-kappaB and mTORC1: expanding roles of the CARMA1 complex. Mol Immunol 2015; 68:546–557.
Kim S, Park MK, Yu HS. Toll-like receptor gene expression during Trichinella spiralis
infection. Korean J Parasitol 2015; 53:431–438.
Scalfone LK, Nel HJ, Gagliardo LF, Cameron JL, Al-Shokri S, Leifer CA et al.
Participation of MyD88 and interleukin-33 as innate drivers of Th2 immunity to Trichinella spiralis
. Infect Immun 2013; 81:1354–1363.
Hawiger D, Inaba K, Dorsett Y. Dendritic cells induce peripheral T cell unresponsiveness under steady state conditions in vivo. J Exp Med 2001; 194:769–779.
Agarwal NB, Jain S, Agarwal NK, Mediratta PK, Sharma KK. Modulation of pentylenetetrazole-induced kindling and oxidative stress by curcumin in mice. Phytomedicine 2011; 18:756–759.
Bar-Sela G, Epelbaum R, Schaffer M. Curcumin as an anti-cancer agent: review of the gap between basic and clinical applications. Curr Med Chem 2010; 17:190–197.
Gradisar H, Keber M, Pristovsek P, Jerala R. MD-2 as the target of curcumin in the inhibition of response to LPS. J Leukoc Biol 2007; 82:968–974.
Lubbad A, Oriowo MA, Khan I. Curcumin attenuates inflammation through inhibition of TLR-4 receptor in experimental colitis. Mol Cell Biochem 2009; 322:127–135.
Dunn IJ, Wright KA. Cell injury caused by Trichinella spiralis
in the mucosal epithelium in mice. J Parasitol 1985; 71:757–766.
Issa RM, El-Arousy MH, Abd EI-Aal AA. Albendazole: a study of its effect on experimental Trichinella spiralis
infection in rats, Egypt. J Med Sci 1998; 19:281–290.
Wranicz MJ, Gustowska L, Gabryel P, Kucharska E, Cabaj W. Trichinella spiralis: induction of the basophilic transformation of muscle cells by synchronous newborn larvae. Parasitol Res 1998; 84:403–407.
Shalaby MA, Moghazy FM, Shalaby HA, Nasr SM. Effect of methanolic extract of Balanites aegyptiaca
fruits on enteral and parenteral stages of Trichinella spiralis
in rats. Parasitol Res 2010; 107:17–25.
Lessard L, Mes-Masson AM, Lamarre L, Wall L, Lattouf JB, Saad F. NF-кB nuclear localization and its prognostic significance in prostate cancer. Br J Urol Int 2003; 91:417–420.
Bell RG. The generation and expression of immunity to Trichinella spiralis
in laboratory rodents. Adv Parasitol 1998; 41:149–217.
Bruschi F, Chiumiento L. Immunomodulation in trichinellosis: does Trichinella
really escape the host immune system? Endocr Metab Immune Disord Drug Targets 2012; 12:4–15.
Peters PJ, Gagliardo LF, Sabin EA, Betchen AB, Ghosh KK, Oblak JB, Appleton JA. Dominance of immunoglobulin G2c in the antiphosphorylcholine response of rats infected with Trichinella spiralis
. Infect Immun 1999; 67:4661–4667.
Du L, Liu L, Yu Y, Shan H, Li L. Trichinella spiralis excretory-secretory products protect against polymicrobial sepsis by suppressing MyD88 via mannose receptor. Biomed Res Int 2014; 2014:898646.
Goodridge HS, Marshall FA, Else KJ, Houston KM, Egan C, Al-Riyami L et al.
Immunomodulation via novel use of TLR4 by the filarial nematode phosphorylcholine-containing secreted product, ES-62. J Immunol 2005; 174:284–293.
Cui L, Miao J, Cui L. Cytotoxic effect of curcumin on malaria parasite Plasmodium falciparum
: inhibition of histone acetylation and generation of reactive oxygen species. Antimicrob Agents Chemother 2007; 51:488–494.
Saqib U, Baig MS. Inhibitors of Toll-like receptor 4 (TLR4) − homodimerization: nipping in the bud. Int J Drug Develop Res 2016; 8:3.
Eckburg PB, Bik EM, Bernstein CN, Purdom E, Dethlefsen L, Sargent V et al.
Diversity of the human intestinal microbial flora. Science 2006; 308:1635–1638.
Magalhaes LG, Machado CB, Morais ER, Moreira EB, Soares CS, da Silva SH et al.
In vitro schistosomicidal activity of curcumin against Schistosoma mansoni
adult worms. Parasitol Res 2009; 104:1197–1201.
De Paula Aguiar D, Brunetto Moreira Moscardini M, Rezende Morais E, Graciano de Paula R, Ferreira PM, Afonso A et al.
Curcumin generates oxidative stress and induces apoptosis in adult Schistosoma
. PLoS One 2016; 11:e0167135.
Lakkany E, Seif El-Din SH. Haemin enhances the in vivo efficacy of artemether against juvenile and adult Schistosoma mansoni
in mice. Parasitol Res 2013; 112:2005–2015.
Nayak A, Gayen P, Saini P, Mukherjee N, Babu SP, Molecular evidence of curcumin-induced apoptosis in the filarial worm Setaria cervi
, Parasitol Res 2012; 111:1173–1186.
Mohapatra AD, Kumar S, Satapathy AK, Ravindran B. Caspase dependent programmed cell death in developing embryos: a potential target for therapeutic intervention against pathogenic nematodes. PLOS Negl Trop Dis 2011; 5:e1306.
Airas N, Sukura A, Pozio E, Nockler K, Meri S. Adaptation of Trichinella nativa
in hosts. MD thesis, Faculty of Veterinary Medicine, University of Helsinki, Finland. 2014. p. 42..
Khan WI. Physiological changes in the gastrointestinal tract and host protective immunity: learning from the mouse-Trichinella spiralis
model. Parasitolofy 2008; 135:671–682.
Wolska A, Lech-Maranda E, Robak T. Toll-like receptors and their role in hematologic malignancies. Curr Mol Med 2009; 9:324–335.
Ashour DS, Othman AA, Shareef MM, Gaballah HH, Mayah WW. Interactions between Trichinella spiralis
infection and induced colitis in mice. J Helminthol 2015; 88:210–218.
Kagan JC. Defining the subcellular sites of innate immune signal transduction. Trends Immunol 2012; 33:442–448.
Beiting DP, Bliss SK, Schlafer DH, Roberts VL, Appleton JA. Interleukin-10 limits local and body cavity inflammation during infection with muscle stage Trichinella spiralis
. Infect Immun 2004; 72:3129–3137.
Despommier DD. How does Trichinella spiralis
make itself at a home? Parasitol Today 1998; 14:318–323.
Kang YJ, Jo JO, Cho MK, Yu HS, Ock MS, Cha HJ. Trichinella spiralis infection induces angiogenic factor thymosin-4 expression. Vet Parasitol 2011; 181:222–228.
Nishida N, Yano H, Nishida T, Ymiro T, Koshida M. Angiogenesis in cancer. Vasc Health Risk Manag 2006; 2:213–219.
Yoysungnoen P, Wirachwong P, Bhattarakosol P, Niimi H, Patumraj S. Effects of curcumin on tumor angiogenesis and biomarkers,COX-2 and VEGF, in hepatocellular carcinoma cellimplanted nude mice. Clin Hemorheol Microcirc 2006; 34:109–115.
Chiumiento L, Bruschi F. Enzymatic antioxidant systems in helminth parasites. Parasitol Res 2009; 105:593–603.
Ashour DS, Shohieb ZS, Sarhan NI. Upregulation of Toll-like receptor 2 and nuclear factor-kappa B expression in experimental colonic schistosomiasis. J Adv Res 2015; 6:877–884.
Trask OJ. Nuclear factor kappa B (NF-κB) translocation assay development and validation for high content screening. In: Sittampalam GS, Coussens NP, Brimacombe K et al.
editors. Assay guidance manual [Internet]. Bethesda (MD): Eli Lilly & Company and the National Center for Advancing Translational Sciences; 2004.
Codina AV, García A, Leonardi D, Vasconi MD, Di Masso RJ. Efficacy of albendazole: β-cyclodextrin citrate in the parenteral stage of Trichinella spiralis
infection. Int J Biol Macromol 2015; 77:203–206.
Dupouy-Camet J, Kociecka W, Bruschi F, Bolas-Fernandez F, Pozio E. Opinion on the diagnosis and treatment of human trichinellosis. Expert Opin Pharmacother 2002; 3:1117–1130.
Abu El Ezz NM. Effect of Nigella sativa
and Allium cepa
oils on Trichinella spiralis
in experimentally infected rats. J Egypt Soc Parasitol 2005; 35:511–523.
Caner A, Döşkaya M, Değirmenci A, Can H, Baykan S, Uner A et al.
Comparison of the effects of Artemisia vulgaris and Artemisia absinthium growing in western Anatolia against trichinellosis (Trichinella spiralis
) in rats. Exp Parasitol 2008; 119:173–179.
Attia RA, Mahmoud AE, Farrag HM, Makboul R, Mohamed ME, Ibraheim Z. Effect of myrrh and thyme on Trichinella spiralis
enteral and parenteral phases with inducible nitric oxide expression in mice. Mem Inst Oswaldo Cruz 2015; 110:1035–1041.
Shehzad A, Khan S, Shehzad O, Lee YS. Curcumin therapeutic promises and bioavailability in colorectal cancer. Drugs Today (Barc) 2010; 46: 523–532.
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